JPH0695164B2 - Color filter - Google Patents

Description

TECHNICAL FIELD The present invention relates to a color filter for various display devices, and more specifically, it is applied to various display devices to enable color display. It concerns color filters.

[Prior art and its problems]

There are various color filters for display devices,
A color filter for a liquid crystal display device will be described below as a typical example.

The liquid crystal display device is for digital display of calculators and electronic watches,
It is widely used as an analog display for measurement / instrumentation equipment, home appliances and audio equipment.

Recently, there has been an increasing demand for color display of this liquid crystal display device mainly for applications such as peripheral terminal display of various devices, vehicle display, telephone display, and television image display. In response to this demand, various color liquid crystal display devices have been proposed, some of which are already in practical use. However, none of the currently proposed color display methods for liquid crystal display devices have been able to sufficiently satisfy the demands of users of the same. Conventionally, as a color filter applied to a liquid crystal display device capable of color display, one formed by forming a gelatin layer on the inner surface of a transparent substrate and dyeing this gelatin layer, it can be dyed on the inner surface of the transparent substrate. Which is obtained by forming a different resin layer and dyeing this resin layer.

However, all of them have the following drawbacks. That is, the color filter of (a) has no heat resistance (a). Therefore, there is a drawback that cracks are generated in the color filter due to heating when the transparent conductive film is formed on the color filter by the vapor deposition method. In order to avoid this defect, there is a defect that the resistance value of the transparent conductive film becomes large and the light transmittance becomes low when vapor deposition is performed at a low temperature.

(B) There is no water resistance. Therefore, there is a drawback that it is difficult to wash with an aqueous solution and the display quality of the liquid crystal is deteriorated due to stains.

The color filter of (a) does not have heat resistance. Therefore, it has the same drawback as shown in-(a). Furthermore, if the heating at the time of forming the transparent conductive film is too high, there are problems such as decomposition, coloring and melting of the resin. Further, even in a temperature range where these problems do not occur, there is a so-called bleeding defect that the dye dyed in a specific pattern moves to an unnecessary portion due to heat and causes color mixing.

[Purpose of the present invention]

An object of the present invention is to provide a color filter which is excellent in heat resistance, water resistance, etc., has sharp pattern edges, and has a smooth surface.

[Structure of Invention]

In view of the various drawbacks described above, the present inventors have completed the present invention as a result of earnest research and experiments, in order to obtain a color filter that can eliminate all the above-mentioned drawbacks. That is, according to the present invention, an active film layer 2 made of at least one of activated alumina or activated silica formed by coating and firing colloidal alumina or colloidal silica alone or a mixture of both on a transparent substrate 1. A dye or dye is formed in the fine pores 3 of the active film layer 2 to form a coloring or pattern, and the fine pores 3 are formed on the fine pores 3 of the active film layer 2. A color filter, wherein the overcoat layer 5 for sealing is formed only of a resin which is not dyed by the dye (4) dyed in the fine pores (3).

Hereinafter, the color filter of the present invention will be described in detail with reference to the drawings.

The transparent substrate 1 used in the present invention may be one that is generally used in liquid crystal display devices, and normally a glass substrate may be used.

On this transparent substrate 1, an active film layer 2 made of at least one of activated alumina or activated silica is formed. In order to form this active film layer 2, first, colloidal alumina, colloidal silica or a mixture of both is applied to the surface of the transparent substrate 1 and dried, and then, for example, at 350 ° C to 850 ° C.
It may be baked for 10 minutes to 180 minutes. The active film layer 2 thus obtained is transparent and has a large number of fine pores 3 formed therein, which form a dyeing layer. The active film layer 2 has a thickness of 0.5 μ in consideration of its transparency, surface hardness, dye receptivity, etc.
A layer thickness of m to 10 μm, preferably 1.5 to 5 μm is desirable. This is because when the layer thickness of the active film layer 2 becomes thick, it becomes white and becomes opaque, and conversely when the layer thickness becomes thin, the dye receptivity decreases and the dyeing density cannot be obtained.

The active film layer 2 is colored or patterned by dyeing the dye 4 in the fine pores 3.
As the dye 4 that can be used in the present invention, there are sublimable dyes and / or dyes that are vaporized by heat melting. Specific examples include disperse dyes, oil-soluble dyes containing no metal, and cationic dyes. There are also dyes which dye with water or a solvent as a medium. Specifically, there are acid dyes, linear dyes, acid mordant dyes, oil-soluble dyes and the like.

For dyeing with a sublimable dye and / or a dye capable of being melt-vaporized by heat, a temperature at which the dye 4 is thermally transferred into the fine pores 3 by using the ink containing the dye 4, which is the dye 4 is used.
Although it depends on the type of, for example, 100 ℃ ~ 250
It may be heated at a temperature of several seconds to 60 minutes. For dyeing with a dye which is dyed with water or a solvent as a medium, the dye 4 is dissolved in a solvent in an amount of 0.01 to 10% and the temperature is from 100 to 100
It may be heated to ℃ and brought into contact with the solvent.

Since very high positional accuracy is required for dyeing each color of the color filter, means for dyeing the dye 4 in the active film layer 2 include, for example, (1) anti-patterned pattern on the active film layer 2. Method of placing the metal mask of No. 1 and removing the metal mask after dyeing (2) Method of forming the active film layer 2 in a pattern and dyeing only that portion (3) Printing of the pattern on the active film layer 2 A method of directly forming a layer and dyeing the ink in the printed layer into the active film layer 2 by heating (4) forming an anti-pattern dye-proof layer on the active film layer 2,
Method of removing the dye-proof layer after dyeing (5) After dyeing the active film layer 2, there is a method of forming a patterned anti-bleaching layer and bleaching unnecessary portions.

The pattern on which the dye 4 is dyed may be appropriately designed according to the application, but the color filter according to the present invention can be easily formed even if it has a shape like a dot pattern. In this case, the pattern formed by dyeing the dye 4 is a pattern composed of two or more colors, and the transparent conductive film 6 formed on the overcoat layer 5 has a pattern corresponding to the pattern of each color. That is, the pattern of each color and the transparent conductive film pattern corresponding to the pattern are formed at positions that exactly match each other.

An overcoat layer 5 for sealing the fine pores 3 is formed on the fine pores 3 of the active film layer 2 on which the dye 4 is dyed. The overcoat layer 5 is formed by applying a hard and highly transparent resin such as acrylic, melamine, epoxy, silicon-based polymer, or polyimide onto the fine pores 3 of the active film layer 2 and then curing the resin. Obtained by heating at temperature. The overcoat layer 5
Is useful for preventing re-evaporation of dye 4 molecules trapped in the fine pores 3 of the active film layer 2, preventing contamination by unnecessary substances, and improving surface smoothness.

When forming the overcoat layer 5, when the color filter obtained by the present invention is covered with the transparent conductive film 6 in a later step, the overcoat layer 5 is adhered to the substance forming the transparent conductive film 6 in an adhesive property. It can be formed using an excellent substance, which greatly contributes to the improvement of the adhesiveness between the color filter and the transparent conductive film 6, and is extremely suitable. The transparent conductive film 6 is the overcoat layer 5
Is formed so as to partially or entirely cover the.

The color filter according to the present invention is constructed as described above, and FIG. 2 shows a schematic sectional view of an example in which the color filter is used in a liquid crystal display device. The transparent conductive film 6 is provided on the color filter, the alignment film 7 is further provided if necessary, the liquid crystal 9 is enclosed between the transparent conductive film 6 and the corresponding substrate 8, and the liquid crystal 9 is sandwiched by one or more polarizing plates 10. Good structure. still,
In the figure, 11 indicates a spacer.

〔The invention's effect〕

The color filter according to the present invention has the following effects because it is configured as described above. That is, since a transparent substrate on which an active film layer made of activated alumina or activated silica is formed is used, it is extremely excellent in heat resistance, water resistance and the like as compared with a conventional color filter. It also has excellent chemical resistance and solvent resistance. The dye for coloring or forming a pattern has excellent surface smoothness because it is dyed on the active film layer. In addition, since the dye for coloring or forming a pattern is dyed in the independent fine pores of the active film layer, there is no problem such as bleeding. Further, since a dye that requires a relatively high temperature and a long time for coloring can be used, therefore, the range of dye selection is broadened. Furthermore, the patterning method can also adopt a simple means.

Therefore, the present invention has extremely high industrial utility value.

[Brief description of drawings]

FIG. 1 is a schematic enlarged sectional view of a color filter according to the present invention, and FIG. 2 is a schematic sectional view of an example in which the color filter according to the present invention is used in a liquid crystal display device. In the figure 1 ... Transparent substrate, 2 ... Active film layer, 3 ... Micropores, 4 ...
… Dye, 4,5 …… Overcoat layer, 6 …… Transparent conductive layer.

 ─────────────────────────────────────────────────── --Continued from the front page Judgment panel for referee Judge Katsunori Ishii Judge Tetsuo Tomita Judge Watanuki Akira (56) References JP-A-55-114589 (JP, A) JP-A-57-190923 (JP, A) Japanese Patent Publication Sho 56-51321 (JP, B2)

Claims (6)

[Claims] 1. An active film layer comprising at least one of activated alumina and activated silica formed by coating a transparent substrate (1) with colloidal alumina, colloidal silica alone or with a mixture of both, and firing. 2) is formed, and the dye (4) is dyed in the fine pores (3) of the active film layer (2) to form a coloring or pattern. An overcoat layer (5) for sealing the micropores (3) is formed on the top of the micropores (3) only by a resin which is not dyed by the dye (4) dyed in the micropores (3). A color filter that is characterized by 2. The color filter according to claim 1, wherein the active film layer has a layer thickness of 1 μm to 10 μm. 3. The color filter according to claim 1, wherein the dye in the fine pores of the active film layer is a sublimable dye and / or a dye capable of being hot melt vaporized. 4. The color filter according to claim 1, wherein the coat layer is covered with a transparent conductive film having a desired pattern. 5. The pattern formed by dyeing a dye is a pattern of two or more colors, the transparent conductive film is a pattern corresponding to the pattern of each color, and the pattern of each color and this 5. The color filter according to claim 4, wherein the color filter is formed at a position that exactly coincides with the transparent conductive film pattern corresponding to. 6. The color according to claim 4, wherein the coat layer is formed by using a resin having excellent adhesiveness with a substance forming the transparent conductive film. filter.